Solar technologies are broadly characterized as either passive solar or active
solar depending on the way they capture, convert and
distribute solar energy. Active solar techniques include the use
of photovoltaic panels and solar thermal collectors to harness the energy.
Passive solar techniques include orienting a building to the Sun,
selecting materials with favorable thermal mass or light dispersing properties, and
designing spaces that naturally circulate air.

In 2011, the International Energy Agency said that "the
development of affordable, inexhaustible and clean solar energy
technologies will have huge longer-term benefits. It will
increase countries’ energy security through reliance on an
indigenous, inexhaustible and mostly import-independent resource,
enhance sustainability, reduce pollution, lower the
costs of mitigating climate change, and keep fossil
fuel prices lower than otherwise. These advantages are
global. Hence the additional costs of the incentives for early
deployment should be considered learning investments; they must
be wisely spent and need to be widely shared".